Piston expander



Dec. 26, 1939. H. DI OW, 2,184,489

PISTON EXPANDER Filed March 22, 1938 Inventor Q X w ,By

A iiorneys Patented Dec. 26, 1939 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to power pistons and more particularly to powerpistons of the type used in internal combustion engines.

Specifically the invention has reference to what may be termed are-camer, the invention being in the nature of an expansible elementadapted to be inserted within the piston and, when arranged within thepiston, to act thereon in a manner to expand the piston at diametricallyopposite points thereon into contact with the cylinder wall to the endthat piston slap will be eliminated and the rings of the piston willhave greater life as a result of the piston being held straight orperpendicular within the power cylinder.

The invention together with its objects and advantages will be bestunderstood from a study of the following description taken in connectionwith the accompanying drawing wherein:

Figure 1 is an elevational view of a piston with parts broken away andshowing the invention as applied thereto, and

Figure 2 is a transverse sectional view through the piston with theinvention applied thereto.

Referring to the drawing by reference numerals it will be seen that 5indicates a conventional piston, such as for example, a Ford V-8 solidskirt steel piston.

Mydevice is indicated by the reference numeral 6 and is in the form ofan elliptical split ring of resilient material such as steel that isadapted to fit within the piston in a manner clearly shown and to act onthe skirt of the piston to force the walls of the piston atapproximately the point A and B on said walls into intimate contact withthe wall of the cylinder, it being noted that the point A is adjacent tothe split in the re-camer 6 while the point B is diametrically oppositeto the point A and to the split in the re-camer 6. The re-camer 6 thusforcing the piston skirt out at the points A and B will cause the pistonskirt to contract or narrow at approximately the 'points C, C, C and Cthus providing sumcient clearance for oil and expansion under heat.

Also to accommodate the reinforcing ribs I provided on the inner side ofthe skirt of the piston the re-camer element 6 has oppositely disposedportions thereof pressed inwardly as at 8, and as clearly shown inFigure 2. As is well known, and as shown in Figure 2 each reinforcingrib I has its free edge sloping upwardly. and inwardly from a pointadjacent the bottom of the piston to the point where it joins thetubular boss 9. The inwardly pressed parts 8 are placed over the lowerparts of these ribs, as shown in Figure 1, and the upwardly and inwardlysloping free edges of the ribs preventthe split ring from movingupwardly for when the piston is expanded at the points A, B by the ringthe contraction at the points 0, C will cause the ribs to closelyapproach or engage the parts 8, it being seen that in Figure 2 thepiston is not shown as being distorted by the ring but is in truecylindrical shape. Thus when the piston is distorted the ribs 1 willapproach very closely to or touch the parts 8 and thus the ribs'willhold the ring against upward movement in the piston and will hold itclose to the inner flange III at the bottom of the pis- It is to benoted, however, that the parts 8 of the ring do not contact the ribswith sumcient force to tend to expand the piston at the points where theribs occur as the ribs simply act to prevent the rings riding upwardlyin the piston. It will also be seen that the ribs i preventcircumferential movement of the ring in the skirt.

My re-camer is especially designed for use with pistons of the solidskirt'type as distin-' guished from pistons having split skirts; and isdistinguished from' a piston expander, since an expander appliespressure at all points around the piston skirt while, as above noted, myrecamer applies pressure to the skirt at only two diametrically oppositepoints thereon, and to an extent eliminating piston slap and a rockingof the piston back and forth at the bottom of the piston.

Thus my re-camer will be found especially useful in reconditioningmotors having worn pistons and cylinder walls since by use of the pistonrecamer piston rings, substituted for the old and removed rings, willhave greater life and mileage capacity. N

It is though that a clear understanding of the construction, utility andadvantages of an inven- 1 tion of this character will be had without amore detailed description.

Having thus described the invention what is claimed as new is:

In combinatioma piston including a solid substantially cylindricalskirt, a pair of diametrically opposed internal bosses in said skirt, apair of re.- inforcing ribs on said bosses, respectively, dependingtherefrom and downwardly diverging relatively, and a split resilientring in said skirt having inwardly bowed portions interengaging withsaid ribs, respectively, for holding the ring against upward andcircumferential movement and said ring reacting outwardly againstdiamet-' so rically opposite portions of the skirt intermediate saidbosses, said ring intermediate said portions being free from contactwith said skirt and loosely engaging said ribs, whereby said skirt isurged I into transversely elliptical form.

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